Nissan Repair: 2002 sentra, fuel pressure regulator, changing spark plugs

Question
i am getting a po300 code. i keep changing spark plugs and they foul a week late or 50 to 100 miles.i have changed the plugs twice now.when i examine the plugs they are wet with fuel.i have spark and good compression.the injectors seem to be o.k. also.it is a 1.8 liter.i am stumped

Answer
Joe,

If the plugs are fouled with fuel (wet) then I would be looking at leaky injectors.  Do a check of the fuel pressure.  Start the car and let it run and then turn it off and see how fast the pressure leaks off.  If it drops fast you have injectors that are leaking and need replacement.  If the fuel pressure is really high, get a Haynes Manual for your car and see the fuel pressure requirements, that would mean the fuel pressure regulator is blown and you have too much pressure.  Email me back with what you find.